Abstract

In this paper, by invoking the laws of irreversible thermody
namics the accelerated expansion of the universe is
explained. It is shown that the entropy of the universe, at an
y particular instant of time, plays a significant role
in the accelerated expansion of the universe. Considering t
he universe to be filled with a classical mono-atomic,
homogeneous and isotropic gas under classical non-equilib
rium situations, two generalized forces causing the
expansion of the universe are arrived at. One of the two force
s, the trivial force, has affinity to volume expansion
and the non-trivial force has affinity to spatial expansion.
The acceleration of the expansion of the universe is due
to the spatial expansion caused by the non-trivial force and
which in turn might account for the presence of the dark
energy. It is shown in this paper that the non-trivial genera
lized force and the dark energy, providing the negative
pressure for spatial expansion, can be explained with irrev
ersible thermodynamics.